In general, twin roll strip casters are used to produce strips having a thickness of several millimeters (mm) by supplying molten steel to a space between a pair of rotating casting rolls.
As shown in FIG. 1, a strip may be produced through a continuous casting process using a twin roll strip caster as follows: molten steel is supplied to a molten steel pool 4 formed by a pair of casting rolls 1, rotated while being cooled with cooling water, and edge dams 2 sealing sides of the casting rolls 1; and thin shells being formed as the molten steel is cooled by contact with the surfaces of the casting rolls 1 are continuously attached at the nip of the casting rolls 1 as a strip having a predetermined thickness.
A meniscus shield 3 is disposed on top of the molten steel pool 4 to block ingress of ambient air, such that molten steel supplied to the molten steel pool 4 may not be oxidized by contact with ambient air, and an inert gas is supplied to the surface of the molten steel through a nozzle installed on the twin roll strip caster for preventing re-oxidation of the molten steel.
Generally, a gas knife or an elastic pad is disposed between the meniscus shield 3 and a center region of the casting rolls 1 to prevent the permeation of ambient air. However, it is relatively difficult to seal both edge portions of the casting rolls 1 because the edge dams 2 may be continuously shaken.
If both edges portions of the casting rolls 1 are not securely sealed as described above, oxides may be formed on the surface of molten steel and may be included in a strip, thereby degrading the quality of edge portions of the strip.
To address this problem, a method of installing sealing members such as elastic pads 5 on top of the edge dams 2 has been proposed as shown in FIGS. 2A and 2B. However, after a long period of use, the elastic pads 5 may be pushed and deformed or separated because of vertical and horizontal shaking of the edge dams 2. In addition, when the elastic pads 5 are excessively compressed by forward movements of the edge dams 2, the edge dams 2 are also excessively stressed.